A couple of weeks ago we announced that a developer preview of Android 7.1 Nougat was on the way. You can get started with this new release today by downloading the SDK and tools. To get the 7.1 release on your eligible device, enroll your device in the Android Beta program. If your device is already enrolled, you'll receive the update automatically.

I got the update on my Nexus 6P late last night, and it installed without any issues.